To provide a rubber composition which improves in processability to a great extent while improving in steering stability and abrasion resistance by incorporating short fibers thereinto, and furthermore can improve in cut resistance and tear resistance, and a pneumatic tire using the same.

The rubber composition comprises a rubber component containing a trans-polybutaiene and short fibers made of a thermoplastic resin, and the pneumatic tire uses this composition. It is preferred that the amount of the short fibers is 0.5-20 pts.wt. based on 100 pts.wt. rubber component, and the amount of the trans-polybutadiene in the rubber component is 0.5 wt.% to 30 wt.%. The short fibers made of a thermoplastic resin preferably have an average length (L) of 0.01 mm to 5 mm, a melting point of 120°C to 150°C, and a ratio (L/D) of the average length (L) to the average diameter (D) of ≥2. The trans-polybutadiene preferably has a trans-bond content of ≥70% and a weight average molecular weight of 1×104 to 20×104.